Method for the interception of GTP-C messages

ABSTRACT

Disclosed is a species of control-message intercept method which includes a passive monitoring approach whereby the relevant control packets are inspected for the purpose of providing additional information for the purpose of facilitating the operation of some primary or ‘master’ Internet Protocol (IP) charging/rating middleware platform/gateway system (intended to equip network operators with the ability to rate and bill IP traffic), and secondly, an invasive technique whereby control (GTP-C) messages are injected for the purpose of altering the state of a given data session in an more aggressive fashion (e.g. to drop a data session when the subscriber runs out of money in his/her prepaid account).

BACKGROUND

Related teachings in the state of the art as U.S. Patent Application20030081607 by Kavanagh, entitled general packet radio service tunnelingprotocol (GTP) packet filter, discloses a method of filtering datapackets in General Packet Radio Service (GPRS) Tunneling Protocol (GTP)signaling messages, whereby selected messages from GTP Path Management,GTP Tunnel Management, GTP Mobility Management, and GTP LocationManagement messages are analyzed against a plurality of filteringcriteria, and data packets that do not meet such filtering criteria aredropped while data packets that meet the criteria are passed. However,the application by Kavanagh speaks to a module for selective filteringof GTP Data packets, whereas our invention of present seeking theprotection of Letters Patent, is largely directed at proxying andfiltering GTP Control packet(s), which are on a separate User DatagramProtocol (UDP) port number and perform a different set of businessoperations.

WIPO Patent Application (WO) 03067830 by Camunas et al., entitled asystem to obtain value-added services in real-time, based on the GeneralPacket Radio Service (GPRS)-network, discloses a system to obtainvalue-added services in real-time based on the General Packet RadioService (GPRS) network, which comprises Serving GPRS Support Node (SGSN)and Gateway GPRS Support Node (GGSN) nodes to enable the access from amobile station to different data networks, using the radio access of aGlobal System for Mobile Communications (GSM) or Universal MobileTelecommunications Service (UMTS) network; wherein between the SGSN andGGSN nodes the invention comprises means to handle GTP protocol datapackets, and wherein the GTP messages traffic, which would haveotherwise flowed directly between the SGSN and the GGSN nodes, isdiverted through said means. When said means detect a GTP message froman SGSN asking a GGSN for the establishment of a GTP tunnel for a PacketData Protocol (PDP) context, said means establish instead two GTPtunnels: one between the Camunas et al.'s invention and the SGSN and theother between Camunas et al.'s invention and the GGSN (once established,the user data packets will arrive through one of the two tunnelsassociated to their PDP Context and will be transferred to the othertunnel). However, Camunas et al.'s invention requires all GTP packets tobe intercepted, whereas the invention disclosed herewith only requiresand speaks to the intermediation of GTP-C (GPRS TunnelingProtocol-Control plane) (the control) packets which remains a moreresourceful approach to advancing the practice of the art. Furthermore,our invention may monitor the GTP-U (GPRS Tunneling Protocol-User plane)packets or alternatively rely on the packet intermediations of themethod for implementing an Internet Protocol (IP) charging and ratingmiddleware platform and gateway system as detailed in patent applicationSer. No. 10/348,972, for the purpose of providing the dataintermediation and intercept functionality on the data plane.(Technicians skilled in the art will recognize that the invention ofpresent need not be limited to the aforementioned method forimplementing an Internet Protocol (IP) charging and rating middlewareplatform and gateway system and other similar network implementationsmay be employed without diluting the intent and scope as such).

REFERENCES CITED

U.S. Patent Application 20030081607 dated May, 2003, to Kavanagh, A. inclass 370/392.

Foreign Patent Document WO 03067830 dated August, 2003.

TECHNICAL FIELD

The present invention relates generally to wireless telecommunicationsand gateway/intercept services; and more specifically, to a method forthe interception of GTP messages.

SUMMARY

Disclosed is a species of control-message intercept method whichincludes a passive monitoring approach whereby the relevant controlpackets are inspected for the purpose of providing additionalinformation for the further additional purpose of facilitating theoperation of some primary or ‘master’ Internet Protocol (IP)charging/rating middleware platform/gateway system (intended to equipnetwork operators with the ability to rate and bill IP traffic), andsecondly, an invasive technique whereby control (GTP-C) messages areinjected for the purpose of altering the state of a given data sessionin an more aggressive fashion (e.g. to drop a data session when thesubscriber runs out of money in his/her prepaid account).

An aspect of the specification provides a method for the interception ofgeneral packet radio service tunneling protocol control (GTP-C)messages.

The method can be part of a computer program product (GTP-C ControlModule), comprising:

a) a computer readable memory medium; and

b) a computer program.

The computer program product can intermediates said telecommunicationstraffic between the Gateway GPRS Serving/Support Node (GGSN) and theServing GPRS Support Node (SGSN).

The computer program product can be articulated to intercept GTP-Cmessages with given fields, states, addresses, contexts and so forth.

The computer program product can be articulated to ignore and/or simplynot process GTP-C messages (generally) or those with given fields,states, addresses, contexts and so forth.

The computer program product can interface with additional networkcomponents to provide further functionality as packet/date rating andclassification, balance query and so forth.

Another aspect of the specification provides a control-message interceptmethod which exists, and is implemented as part of a computer programproduct, whereby control packets are passively monitored for the purposeof providing additional information for the further additional purposeof facilitating the operation of some primary or master InternetProtocol (IP) charging/rating middleware platform/gateway system(intended to equip network operators with the ability to rate, charge,and intermediate IP traffic), and secondly, an invasive techniquewhereby control (GTP-C) messages are modified, injected, or deleted forthe purpose of altering the state of a given data session in an moreaggressive fashion (including, where for instance, a data session needbe dropped when the subscriber runs out of money in his/her prepaidaccount).

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a typical, non-limiting embodiment of the systemlevel architecture employed in the disclosure of present.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Members skilled in the art will recognize that the ensuing represents anillustrative recital of the preferred embodiments of the invention ofpresent and other embodiments may be articulated, gleaned andarticulated from such while still remaining within its spirit and scope.Indeed equivalents found within the state of the art, and those whichmay reasonably and effectively be deemed equivalent in the future shouldalso be understood as being incorporated by reference hereto and such.Furthermore, much of the language has been illustrative and is to beconstrued as expressly for pedagogical purposes in helping elucidate theart as concisely and beneficially as practical.

The method for the interception of GTP messages disclosed herewith isimplemented as part of a computer program product, hereinafter, theGTP-C Control Module.

FIG. 1 represents the preferred illustrative embodiment of theinvention's architecture and, as such, depicts a fault redundant GTP-CControl Module pair 30A, 30B surrounded by Load Balancers 20A, 20B (oneLoad Balancer 20A on the side of the SGSN 10, the other Load Balancer20B on the side of the GGSN 50). FIG. 1 also depicts a wirelesssubscriber handset 60 that connects to SGSN 10 via a wireless antenna 70and a base station sub-system (BSS) 80. The architecture in FIG. 1 isconfigured to carry telecommunication traffic GTP messages betweenwireless subscriber handset 60 and GGSN 50 via SSGN 10.

In alternative embodiments, only a partial GTP-C stack need bearticulated and developed when only handling a fraction of the totalityof the messages. (These operations are CreateContextRequest/Response,UpdateContextRequest/Response and DeleteContextRequest/Response,although practitioners may well realize that other iterations andoperations may be articulated). In this alternative embodiment, for theremainder of the messages, we need only be able to identify them asGTP-C messages and forward them on. (Indeed, this art is not intended torepresent a proxy design. The GTP-C connection is generally notterminated at the GTP-C Control Module 30A 30B).

The method for the interception of GTP messages, in the preferredembodiment (though of course not necessarily), may also beco-articulated and implemented with the method for implementing anInternet Protocol (IP) charging and rating middleware platform andgateway system as detailed in patent application Ser. No. 10/348,972, toenhance the packet/data rating and classification mechanisms inherent inthe invention disclosed hereto. Technicians skilled in the art willrecognize that the invention of present need not be limited to theaforementioned method for implementing an Internet Protocol (IP)charging and rating middleware platform and gateway system and othersimilar network implementations may be employed without diluting theintent and scope as such.

Now, in continuing with reference to FIG. 1, upon detection of aCreateContextRequest (for instance), said message will be delayed whilethe method for implementing an Internet Protocol (IP) charging andrating middleware platform and gateway system 40A 40B (as detailed inpatent application Ser. No. 10/348,972) is contacted for balance query.(Technicians skilled in the art will recognize that the invention ofpresent need not be limited to the aforementioned method forimplementing an Internet Protocol (IP) charging and rating middlewareplatform and gateway system and other similar network implementationsmay be employed without diluting the intent and scope as such). Themessage is then forwarded on to the GGSN 50 for context creation and theresponse forwarded back to the SGSN 10 by the GTP-C Control Module 30A30B. For deleting a context (as, when a subscriber has run out ofbalance), the method for implementing an Internet Protocol (IP) chargingand rating middleware platform and gateway system 40A, 40B, willinitiate the delete request to the GTP-C Control Module 30A, 30B. TheGTP-C Control Module 30A 30B will in turn send delete requests to boththe GGSN 50 and SGSN 10 using spoofed packets.

In alternative embodiments, said deletePDPContext message can alsoinitiate by the SGSN 10 or GGSN 50 where the GTP-C Control Module 30A30B intercepts the message, and further triggers the session deletion toIP charging and rating middleware platform and gateway system 40A 40B.The deletePDPContext may then be simply forwarded by the GTP-C ControlModule 30A 30B to the GGSN 50 or SGSN 10 depending on the initiator ofthe deletePDPContext message.

1. A method for the interception of General Packet Radio Service (GPRS)control (GTP-C) messages, comprising: intercepting a GTP-C message at acontrol module, said control module configured to intercept GTP-Cmessages with one or more specified fields, states, addresses, orcontexts and to ignore GTP-C messages with one or more of otherspecified fields, states, addresses, or contexts; said control moduleresiding between a Serving GPRS Support Node (SGSN) and a Gateway GPRSSupport Node (GGSN); performing a balance query to determine if awireless subscriber device has a sufficient balance; forwarding saidmessage from said control module to said GGSN if said wirelesssubscriber device has a sufficient balance; and, causing modification ofsaid GTP-C message if said subscriber device has insufficient balance,wherein said modification comprises sending delete requests from saidcontrol module in the form of spoofed packets to each of the SGSN andthe GGSN.
 2. The method of claim 1, where the modification of said GTP-Cmessage can include the deletion of the GTP-C message or replacement ofthe GTP-C message with at least one GTP-C message.
 3. The method ofclaim 1, where said balance query is performed by at least oneadditional network component configured to provide packet/data ratingand classification in addition to said balance query.
 4. The method ofclaim 3 wherein said additional network component is a charging andrating middleware platform and gateway system.
 5. A system for theinterception of General Packet Radio Service (GPRS) control (GTP-C)messages, comprising: a control module for intercepting a GTP-C messagereceived from a Serving GPRS Support Node (SGSN) connected to saidcontrol module, said control module configured to intercept GTP-Cmessages with one or more specified fields, states, addresses, orcontexts and to ignore GTP-C messages with one or more of otherspecified fields, states, addresses, or contexts; said control modulefurther connected to a Gateway GPRS Support Node (GGSN); said messageoriginating from a wireless subscriber device and carried to saidcontrol module via said SGSN; said control module further configured toinitiate a balance query to determine if said wireless subscriber devicehas a sufficient balance; said control module further configured toforward said message from said control module to said GGSN if saidwireless subscriber device has a sufficient balance; and, said controlmodule further configured to cause deletion of said GTP-C message ifsaid subscriber device has insufficient balance, by sending deleterequests in the form of spoofed packets to each of the SGSN and theGGSN.
 6. The control module of claim 5 wherein said balance query isperformed by at least one additional network component configured toprovide packet/data rating and classification in addition to saidbalance query.
 7. The control module of claim 6 wherein said additionalnetwork component is a charging and rating middleware platform andgateway system.
 8. A non-transitory computer-readable medium storing aplurality of programming instructions; said programming instructionsexecutable on a control module; said programming instructions forconfiguring said control module to perform a method for the interceptionof General Packet Radio Service (GPRS) control (GTP-C) messages; saidmethod comprising: intercepting a GTP-C message at said control module,said control module configured to intercept GTP-C messages with one ormore specified fields, states, addresses, or contexts and to ignoreGTP-C messages with one or more of other specified fields, states,addresses, or contexts; said control module residing between a ServingGPRS Support Node (SGSN) and a Gateway GPRS Support Node (GGSN);performing a balance query to determine if said wireless subscriberdevice has a sufficient balance; forwarding said message from saidcontrol module to said GGSN if said wireless subscriber device has asufficient balance; and, causing deletion of said GTP-C message if saidsubscriber device has insufficient balance, wherein said deletioncomprises sending delete requests from said control module in the formof spoofed packets to each of the SGSN and the GGSN.